That should be mostly the default. My secondary Vega 64 is reporting using only 3W which, on a laptop would be worth it but I doubt 3W affects your electricity. It's nothing compared to the overall power usage of the rest of the desktop, the monitors. Pretty sure even my fans use more.

The best way to address this would be to first take proper measurements. Maybe get a kill-a-watt and measure usage with and without the card installed to get the true usage at the wall. Also maybe get a baseline with as little hardware as possible. With that data you can calculate roughly how much it costs to run the PC and how much each component costs, and from there it's easier to decide if it's worth.

Just the electric bill being higher isn't a lot to go with. Could just be that it's getting cold, or hot. Little details can really throw expectations off. For example, mining crypto during the winter is technically cheaper than not for me because I have electric heat, so between 500W in a heating strip or 500W mining crypto, they both produce the same amount of heat in the room but one of them also made me a few cents as a byproduct. You have to consider that when optimizing for cost and not maximizing battery life on a laptop.